The present invention relates to devices used to seal vehicle fluid systems.
Many of today""s vehicles include numerous fluid based systems that incorporate several pressure modulators, e.g., solenoid valves, that control the flow of hydraulic fluid therein. As but one example, an anti-lock braking system, used to maintain vehicle control during extreme braking, is capable of modulating the pressure in the wheel brake cylinders in order to keep the wheels from slipping on the roadway during harsh braking conditions.
A typical anti-lock brake system can include several solenoid valves to control the hydraulic fluid pressure in the individual components, e.g., a master cylinder, and a plurality of wheel cylinders. Usually a solenoid valve is installed between the master cylinder and each wheel cylinder. In order to prevent fluid leaking from the ABS, a seal must be included between the solenoid valve and the corresponding bore in which the valve is inserted. The seal also isolates the parts, i.e., the valve and the corresponding fitting in which it is installed, from each other. The seal must operate under extremely harsh conditions, e.g., extreme temperatures, corrosive fluids, extreme vibration, and high fluid pressures. Elastomer seals supported by nylon back-up rings have been used in the harsh conditions described above. Unfortunately, component tolerances can produce radial clearances between the back-up ring outer diameter or back-up ring inner diameter and adjacent surfaces and these radial clearances can lead to seal extrusion. Additionally, while the valve is being inserted in its corresponding bore and during the life of the valve, the seal back-up ring can fracture unpredictably and uncontrollably and lead to seal extrusion, which can ultimately lead to leakage and failure of the valve.
The present invention has recognized the above-mentioned prior art drawbacks, and has provided the below-disclosed solutions to one or more of the prior art deficiencies.
An anti-extrusion ring has a plano-concave cross-section and is used in conjunction with a vehicle solenoid valve. In a preferred embodiment, the solenoid valve includes a filter that forms a seal contact face. A seal surrounds the solenoid valve adjacent to the seal contact face. The anti-extrusion ring is installed around the solenoid valve such that it is sandwiched between the seal and a flange. Preferably, the anti-extrusion ring is installed in a bore such that a bore-to-ring interference area is formed between the bore and the anti-extrusion ring and a debris capture area is formed above the bore-to-ring interference area.
If the anti-extrusion ring fractures during the installation of the solenoid valve or during the life of the solenoid valve, debris capture area prevents any debris from entering the fluid system in which the solenoid valve is installed. Moreover, the anti-extrusion ring deforms in such a manner to account for variations in the outer diameter of the solenoid valve and variations in the inner diameter of the fitting due to the predetermined manufacturing tolerances of these parts. As such, extrusion of the seal due to high fluid pressure is reduced or eliminated.
In another aspect of the present invention, a solenoid valve includes a valve fitting that forms a bore. Disposed within the bore is a solenoid valve that forms a seal contact face. A flange is installed around the solenoid valve to hold the solenoid valve within the bore and a seal is disposed around the solenoid valve in contact with the seal contact face. An anti-extrusion ring is sandwiched between the flange and the seal. In this aspect of the present invention, the anti-extrusion ring is configured such that a bore-to-ring interference area is formed between the bore and the anti-extrusion ring and a debris capture area is formed above the bore-to-ring interference area.
In still another aspect of the present invention, a fluid connection includes a fluid fitting that is formed with a bore. A fluid device is disposed within the bore and includes a first physical member and a second physical member installed there around. A seal is disposed around the fluid device in contact with the second physical member. Moreover, an anti-extrusion ring is sandwiched between the first physical member and the seal.